Download Chapter 5

New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5
LANs and WLANs
At a Glance
Instructor’s Notes


Chapter Approach
Chapter Notes
Network Building Blocks
Quick Quiz
Classroom Activity
Wired Networks
Quick Quiz
Classroom Activity
Wireless Networks
Quick Quiz
Classroom Activity
Using LANs
Quick Quiz
Classroom Activity
Security through Encryption
Quick Quiz
Classroom Activity
Issue: Who’s Stealing My Signals?
Computers in Context: Education


Chapter Discussion Questions
Chapter Key Terms
Chapter 5-1
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-2
Instructor’s Notes
CHAPTER APPROACH
Chapter 5 focuses on local area networks (LANs) and wireless LANs (WLANs), including cables
and devices that connect computers on networks, types of networks, protocols, packet switching
and circuit switching, file sharing, security measures, and encryption.

Section A introduces the fundamental components of networks, such as classifications,
devices, topologies, network links, and communication protocols.

Section B extends the discussion of LANs, including a discussion of HomePNA and
powerline networks, and Ethernet equipment and setup.

Section C focuses on wireless networks, including Bluetooth technology as well as Wi-Fi
equipment and setup.

Section D outlines the advantages and disadvantages of using LANs, and the options for
sharing files and printers, as well as troubleshooting LANs.

Section E discusses the importance of Wi-Fi security and the need for encryption to
protect the users of wireless network.

The Issue section of the chapter focuses on the current reality of the wide availability of
unsecured wireless networks, and the legal and commercial implications.

The one Course Lab for this chapter gives students an opportunity to learn more about the
networking utilities installed on their own computer.
COURSECASTS
Introduce your students to the latest in technology news and updates by utilizing our latest online
feature, CourseCasts. This online resource is meant to keep your students informed and
interested in the latest in technology news through podcasts. Direct your students to
http://coursecasts.course.com, where they can download the most recent CourseCast onto their
mp3 player. CourseCasts are authored by Ken Baldauf, a faculty member of the Florida State
University Computer Science Department, who teaches technology classes to thousands of FSU
students each year. CourseCasts offer a great opportunity to open or close your lecture with a
discussion based on the latest in technology news.
CHAPTER NOTES
If your school uses a network, try to set up a computer in your classroom that has a network and
Internet connection. Also, install a projection system to this computer so that you can demonstrate
networking concepts covered in this chapter.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-3
SECTION A: NETWORK BUILDING BLOCKS
Network Classifications
In this section students learn about categorizing networks according to their geography, that is, by
the physical location of the different networked computers. Key terms include PAN, LAN, NAN,
WAN, and MAN.
Discussion topics include:

Stress that early PCs were designed for solo use, yet the advantages of networking were
identified as early as 1976.

What good is information, if you cannot share it easily with other people? Shared
resources soon followed as an identifiable advantage of networking. Ask students to list
the benefits of shared resources and information. Is there a downside?

Describe the different scopes. Which of these are familiar to students? Why is it
important (or convenient) to describe networks in terms of their scope?
Student Edition Lab: Refer students to the New Perspectives Web site for a Student Edition Lab
called “Networking Basics.”
LAN Standards
In this section students learn about the movement to standardize LANs.
Discussion topics include:

What would the repercussions have been of the diversity of LAN technologies that
existed previously? What advantages exist in the consolidation around Ethernet
technology and Wi-Fi standards?
Network Devices
This section describes the devices that can be attached to a network and how computers connect
to LANs. Key terms include node, network interface card, networked peripheral, network
attached storage, and network device.
Discussion topics include:

Most students have had experience with a LAN, though they may not know it! When they
use a computer in the library to print a document, or access the Internet, they are using a
LAN. Use this as an example to stress that in many cases using a LAN is transparent.
Clients, Servers,, and Peers
This section describes a method for categorizing networks according to the organizational
structure, and for categorizing servers according to their function. Key terms include application
server, file server, print server, peer-to-peer mode, and client/server mode
Discussion topics include:

What is the difference between peer-to-peer mode and client/server mode? Use Figures 54 and 5-5 to illustrate the difference between client/server and peer-to-peer networking.
What kind of structure does your school network use?
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-4
Physical Topology
This section discusses how the devices on an individual network can be physically arranged; this
is known as physical topology. Key terms include star topology, ring topology, bus topology,
mesh topology, tree topology, bridge, and gateway.
Discussion topics include:

Review the different types of topologies, and the advantages and disadvantages of each.
For example, a bus topology allows quick and cost-efficient communication of one signal
to many users.

The most common uses of different topologies. For example, star topologies are used
with telephone lines, bus topologies with cable lines, and ring topologies with some local
area networks.

Use Figure 5-6 to describe the major topologies. Describe how gateways can connect
networks to one another, even those with different topologies. Use the board to draw a
series of interconnected networks.
Network Links
This section explains how the nodes on a network are connected to one another. Key terms
include communications channel, bandwidth, broadband, and narrowband.
Discussion topics include:

The different types of communication links available. A communications link enables
data transmission through cables, transmitters, and satellites. As technology continues to
advance quickly in this area, students should understand the various methods, with their
advantages and disadvantages, for data communication. All networks, whatever their
geographic scope, organizational structure, and physical topology, rely on some form of
link.

Define bandwidth, using the highway example given in the book. Discuss the bandwidths
of the various forms of connections like fiber-optic cables, radio waves, infrared light,
twisted-pair cable, coaxial cable, etc.
Communications Protocols
This section discusses the fundamentals of communications protocols. Key terms include
handshaking, packet, packet switching, circuit switching, MAC address, IP address, octet,
and DHCP.
Discussion topics include:

Define a protocol: a set of rules that describe how parties should communicate. Stress
that the protocols that govern communication over networks and the Internet are very
complex, and that you don’t expect students to understand them in great detail.

Compare protocols to spoken language. In order for two people to communicate, they
must share a common language. If one person speaks only Danish and the other only
Hebrew, they won’t be able to communicate. But if both also speak English, they could
agree to use that as a common language. Likewise, networks must agree on a common
language. The language, or protocol, of the Internet, is TCP/IP. While some networks use
other communication protocols, they must also be able to “speak” TCP/IP in order to
communicate over the Internet.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-5

Describe what a communications protocol can do, beginning with dividing data into
packets, and moving on to packet routing. Explain briefly how packets are assembled at
the destination to make a complete message.

Make sure students understand the difference between a circuit switching network (like
the telephone system) and a packet switching system (the Internet, and local area
networks). Networks designed for computer data typically use packet switching
technology, in which a message is divided into small units, called packets, and each
packet is addressed to the same destination. The method for creating packets, sending
packets from one device to another, and preventing packets from colliding depends on the
network access method and communications protocol.

Compare a telephone network’s circuit switching technology with a computer network’s
packet switching technology. Ask students why packet switching is a more robust way to
transport data.
Quick Quiz
1. A local area network that treats every computer as an equal, is known as a(n)
___________________ network.
2. True/False: In the past, a great diversity of LAN technologies existed but today, LANs
are standardized on a single standard: Ethernet.
3. Networks that connect all devices in a circle, with each device having exactly two
neighbors, use which topology?
a. Star topology
b. Ring topology
c. Bus topology
d. Mesh topology
Quick Quiz Answers
1: Peer-to-peer
2: False
3: b
Classroom Activity
Open up your classroom computer, and show the students the network card. If possible, use old
computer to have students practice inserting network cards into expansion ports.
SECTION B: WIRED NETWORKS
Network Links
This section explains how the nodes on a network are connected to one another. Key terms
include wired network, HomePNA, and powerline network.
Discussion topics include:

Ask if any students are familiar with these technologies. They are not yet widely
available. Point out that they are slow, compared to Ethernet. Can students think of
situations where these technologies might be preferred, despite their slow speed?
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-6
Ethernet
This section explains one of the most common standards, Ethernet. Key terms include
CSMA/CD, Fast Ethernet, and Gigabit Ethernet.

Ethernet has a large installed base. 85 percent of all LANs use Ethernet technology.

Packet behavior. The Ethernet standard defines how packets are passed along the
network, what happens when two or more packets collide, the speed at which packets
travel and what sort of cables and topology the network uses. Use Figures 5-15, 5-16, and
5-17 to discuss the specifics of Ethernet and its requirements.

Review the reasons for the success of the Ethernet standard, as listed on page 259.
Which, if any, of these reasons stands out as the main reason why Ethernet became so
popular?
Ethernet Equipment
This section provides an overview of the equipment necessary for an Ethernet network. Key
terms include Ethernet adapter, network hub, network switch, network router, and RJ45
connector.
Discussion topics include:

The key hardware component for connecting a computer to a local area network is a
network interface card, or NIC. A NIC is typically inserted into an expansion slot or
PCMCIA slot, and then connected by cable to a device called a network hub, which is a
centralized connection point for all of the network devices.

If you have a network card that is not in use, you might bring it to class as a visual aid.
Ask your tech support department if they have any "dead" network cards you could have.
Other network equipment, such as hubs, routers, and repeaters, would be helpful to
present in class.
Ethernet Setup
This section provides an overview, in photographs, of the procedure for installing a LAN.
Discussion topics include:

Have any students set up a home network? Refer to the photographs in Figure 5-23 when
discussing how to set up a network.

Demonstrate My Network Places in Windows to show students how to make folders and
drives available to other users.
Course Lab: The New Perspectives Lab “Local Area Networks” deals with issues that relate to
this section of the textbook. You might want to go through the lab during class time if you have a
computer with a projection device. Or, assign this lab for students to do on their own.
Quick Quiz
1. The devices in an Ethernet are connected with network cables terminated at each end
with a plastic _______________ connector.
2. True/False: Desktop computers can retain their mobility when they are not tethered to a
cable.
3. A network ______________ is a device that links two or more nodes of a wired network.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-7
a. hub
b. router
c. switch
d. adapter
Quick Quiz Answers
1: RJ45
2: False
3: a
Classroom Activity
Does your classroom have a computer that is connected to a campus network? If so, have the
class examine the connections. What kind of cable is in use? To what kind of device is the
computer connected? A hub? Something else? If the connection is wireless, where is the wireless
hub? If necessary, take a field trip to the hub to see what it looks like. Does your building have a
cable room (or closet) where network connections come together? Visit that room as well.
SECTION C: WIRELESS NETWORKS
Wireless Basics
In this section, students learn about Wi-Fi technology and WLANs. Key terms include wireless
network, RF signals, transceiver, microwaves, and infrared light.
Discussion topics include:

Wi-Fi specifies the hardware, the type of transmission medium and the transmission
speed.

If your campus offers a wireless network, ask the class if they use it. Is it reliable?

Radio waves and infrared options. Most students will be familiar with the use of radio
waves for data communication. However, many will not be familiar with the use of
infrared transmissions, even though they use some infrared devices, such as television
remote controls.

Advantages and disadvantages of various types of network links. Use the following chart:
Communications Link
Advantages
Disadvantages
Twisted-pair cables
Most typical communications
link means already miles of it
in place; shielded twisted pair
(STP) cable helps reduce signal
noise; unshielded twisted pair
(UPT) cable is less expensive
Limited capacity for data
communications; STP cable is
more expensive than UTP cable,
but the latter is more susceptible
to signal noise
Coaxial cables
Can carry signals for more than
100 TV channels
simultaneously; good capacity
for data communications
Less durable, more expensive,
and more difficult to work with
than twisted-pair cable
Fiber-optic cables
Light signals encounter little
Multi-mode cable, though easy
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-8
resistance when moving
through the glass cable,
meaning can travel longer
distances; single-mode cable
has exceedingly high
transmission speeds; multimode cable easy to install
to install, has a relatively wide
core, resulting in signal
distortion and reduced
bandwidth
Radio waves
Provide wireless transmission
Before you can use a frequency
for communication, it must be
licensed from the FCC
Infrared transmissions
Provide wireless transmission;
an FCC license is not required
Depends on line-of-sight
communication
Microwave transmissions
Provide wireless transmission
by sending a high-frequency
radio signal
Microwave stations cannot be
more than 25 or 30 miles apart
Satellite links
A GEO satellite provides
continuous coverage over a
particular area; an LEO satellite
offers transmission delays of
only a few hundredths of a
second
A GEO satellite requires a delay
of 24 seconds to transmit data;
an LEO satellite requires a web
of satellites
Bluetooth
This section provides an introduction to Bluetooth technology and Bluetooth networks, or
piconets.
Discussion topics include:

The name Bluetooth is derived from the nickname of a 10th century Danish king, Harald
Bluetooth. According to the inventors of the Bluetooth technology, Harald engaged in
diplomacy that led warring parties to negotiate with each other, making Bluetooth a
fitting name for their technology, which allows different devices to talk to each other.

Are there other uses like the wireless headsets that clips to a motorcycle helmet, as shown
in Figure 5-28, that students can envision for Bluetooth technology?
Wi-Fi
This section provides an overview of Wi-Fi technology, and includes a key term, MIMO.
Discussion topics include:

Emphasize that the maximums listed in the table in Figure 5-29 are theoretical
maximums because of the obstacles that wireless signals face in the typical office
environment, for example.
Wi-Fi Equipment
This section explains the type of equipment needed for a Wi-Fi network. Key terms include: WiFi card, wireless ad-hoc network, wireless infrastructure network, wireless access point, and
wireless router.
Discussion topics include:

Compare the equipment needed for a LAN with the equipment needed for a Wi-Fi
network.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-9

Survey students about the wireless capability of their own computers. Do their desktop
computers have a Wi-Fi card or did they come pre-equipped with wireless capabilities?
What capabilities do their laptops have?

Discuss the advantages of a wireless ad-hoc network over a wireless infrastructure
network. Present real-world scenarios to students that require one kind of solution or the
other and ask them to identify which type of network would be preferred, and why.
Wi-Fi Setup
This section discusses the steps involved in setting up a Wi-Fi network, and includes a key term,
SSID.
Discussion topics include:

An extremely weak form of wireless network security is to turn off the broadcast of the
SSID. While to the average user there does not appear to be a network in use, a network
protected in this way is still easily accessed by crackers using the appropriate tools. Other
forms of encryption and authentication should also be used, at a minimum WEP but
preferably WPA. Today, some newer wireless access points disable the automatic SSID
broadcast feature in an attempt to improve network security. Advanced wireless access
points support broadcasting multiple SSIDs, allowing the creation of Virtual Access
Points; this partitions a single physical access point into several logical access points,
each of which can have a different set of security and network settings.
Student Edition Lab: Refer students to the New Perspectives Web site for a Student Edition Lab
called “Wireless Networking.”
Quick Quiz
1. ______ technology uses two or more antennae to essentially send multiple sets of signals
between network devices.
2. True/False: Microwaves can be aimed in a single direction and have more carrying
capacity than radio waves.
3. IEEE 802.11n has a (theoretical) speed of ______.
a. 11 Mbps
b. 26 Mbps
c. 54 Mbps
d. 200 Mbps
Quick Quiz Answers
1: Ping
2: True
3: d
Classroom Activity
What are some advantages and disadvantages of wireless networks? Is the connection always
available? Do the advantages outweigh the disadvantages with regard to this technology? Is the
answer to this contingent on circumstances?
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-10
SECTION D: USING LANS
LAN Advantages and Disadvantages
This section provides an overview of the advantages and disadvantages of LANs, including a
discussion of the benefits of shared resources.
Discussion topics include:

Review the advantages alongside the challenges listed in the text. Do students have
experience with the benefits, like the shared hardware, or the increased productivity?
Have students had the unfortunate exposure to the downsides of LANs, like having a
wireless LAN snooped on or receiving a virus via a network connection?
Sharing Files
This section discuss file sharing using a LAN, and includes a key term, drive mapping.
Discussion topics include:

Review the features of the Workgroup Leader Properties dialog box in Figure 5-43.
Discuss how these options allow various levels of access to the files on the network.

File servers for use on home networks. As the costs of file servers decline, and the
number of computers in a single home continues to rise, file servers for home use can be
something to consider. Students may well be able to relate to having had a file
exclusively on their laptop, for example, when the laptop failed; having had a file server
at home that made backup as easy as dragging and dropping a file could have made a
significant difference given the failure of an individual machine.
Sharing Printers
This section reviews the use of printers across a network.
Discussion topics include:

Use Figure 5-45 to consider the different ways in which a printer can be attached to a
LAN, and use Figure 5-46 to talk about the options in the printer dialog box that permit
the sharing of this resource across the network.
LAN Parties
In this section, students learn what a LAN party is and what hardware and software are involved
in a LAN party.
Discussion topics include:

A controversy among those in the LAN party community is advertising at LAN parties,
Some events have gained a reputation as an advertising front for companies (e.g., Bawls,
Alienware) in order to generate sales or demonstrate their products to the gaming
audience. However, many large-scale LAN parties actively seek sponsorship, in order to
reduce operating risk to the organizers and to provide prizes for attendees.

LAN party attendees tend to be more experienced gamers as the setup required makes
LAN parties too much of a commitment for casual players.
Troubleshooting
This section discusses factors to consider if a LAN stops working.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-11
Discussion topics include:

Share with students which among the problems listed on page 281 are the most common.
Are there other problems to include in this list?
Quick Quiz
1. _________ assigns a drive letter to a storage device located on a network workstation.
2. True/False: Network computers are vulnerable to unauthorized access from many sources
and locations.
3. For security reasons, it is not advisable to allow shared access to the __________
directory of drive C on your computer.
a. root
b. home
c. network
d. shared
Quick Quiz Answers
1: Drive mapping
2: True
3: a
Online Activity
What kinds of LAN parties are open to gamers in the area where you are located? Ask students to
use the Internet to find the Web site(s) of LAN parties in the area and learn about what is
involved and what software/hardware is required for participation. How much does it cost to be a
part of the event?
SECTION E: SECURITY THROUGH ENCRYPTION
Wi-Fi Security
This section provides an overview to the threats to a wireless network. Key terms include: LAN
jacking, war chalking, wireless encryption, WEP, WPA, WPA2, and wireless network key.
Discussion topics include:

LAN jacking. When the laptop's wireless adapter (NIC) is set to promiscuous mode, it
will receive any packets within its range. The goal is to find vulnerable sites either to
obtain free Internet service or to potentially gain illegal access to the organization's data.
The legality of wardriving in the United States is not clearly defined at this point. There
has never been a conviction for wardriving, and there is the untested argument that the
802.11 and DHCP protocols operate on behalf of the owner giving consent to use the
network, but not if the user has other reason to know that there is no consent. A New
Hampshire bill, which would clarify that the duty to secure the wireless network lies with
the network owner has not passed yet, due to concerns that it may create a loophole for
criminal activity. The specific laws vary from state to state.
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-12
Encryption
This section discusses the use of encryption to protect transmissions over a network. Key terms
include: plaintext, ciphertext, decryption, cryptographic algorithm, cryptographic key, weak
encryption, strong encryption, AES, brute-force method, symmetric key encryption, public
key encryption, and PGP.
Discussion topics include:

Use the example of the code in Figure 5-53 as an example of weak encryption. Discuss
the flaws of this technique and the ways in which a code has to be changed in order to be
considered strong encryption.

A good analogy for explaining public key encryption (PKE) is that of a locked front door
to a building, and the door has a mail slot. The mail slot is exposed and accessible to the
public; its location (the street address) is analogous to the public key. Anyone knowing
the street address can go to the door and drop a written message through the slot.
However, only the person who possesses the matching private key, the owner of the
building in this example, can open the door and read the message.
Quick Quiz
1. _________ key encryption uses the same key to encrypt the message as to decrypt it.
2. True/False: War chalking is based on a convention established by hobos during the Great
Depression of the 1930s.
3. __________ uses the same kind of strong encryption required by government agencies
and businesses.
a. WPA2
b. WPA
c. TKIP
d. WEP
Quick Quiz Answers
1: Symmetric
2: True
3: a
Online Activity
History abounds with fascinating stories about encryption and cryptography, including, notably,
the use by the Germans of the Enigma cipher machine in World War II. Ask students to use the
Internet to read about the Enigma machine and the role that device played in German dominance
early in the war. How did the machine work to encrypt the messages of the German military?
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-13
ISSUE
Who’s Stealing My Signals?
As this section emphasizes, the world of wireless networks is a brave new world in terms of
legality and commerce. Advocates of free WLANs envision a nationwide web of interconnected
Wi-Fi networks at the same time that broadband providers fear that each user of a free wireless
network is one less subscribers to their services.
Consider dividing the class into two groups. Have one group come up with reasons why
piggybacking on a neighbor’s wireless network should be prosecuted and treated as serious
criminal activity. Have the other group come up with reasons why this practice should be treated
lightly. Ask the groups to share their reasoning with each other. Which arguments do the students
find most compelling? Have students themselves ever accessed an unprotected wireless network
without the permission of the network’s owner?
COMPUTERS IN CONTEXT
Education
Ask students to relay some of their early experiences with computers in the classroom. Discuss
the options offered at your school, such as distance learning.
CHAPTER DISCUSSION QUESTIONS
1
Network technology is changing rapidly. What problems do networks still need to solve? Do
you think networks themselves will be eclipsed by some other type of technology? If so, what
characteristics would it have?
2
The Internet has experienced unprecedented growth in recent years and is now part of global
life. As the “network of networks,” what special technological and ethical problems do
Internet users need to solve? Are the technological and ethical problems any different for
those who create technology for the Internet? Do you think the growth of the Internet should
be limited?
3
What is your idea of the ideal Internet access? What is necessary to make that happen?
4
Home networks are becoming increasingly popular. Why would anyone want a home
network? What advantages do they offer to home users? What are the drawbacks?
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-14
Key Terms
AES
The technology used for WPA2, one of the strongest encryption algorithms
Application server
Runs application software for network workstations
Bandwidth
Transmission capacity of a communications channel
Bluetooth
Wireless standard operates at speeds up to 700 Kbps
Bridge
A device that connects two networks, and which simply transfers data without
regard to its format
Broadband
High-bandwidth communications systems
Brute-force method
The attempt to break codes by trying all possible keys
Bus topology
A network topology that joins all devices along a common backbone, in a row,
like seats on a bus
Ciphertext
An encrypted message
Circuit switching
Establishes a private link between one telephone and another for the duration of
a call
Client/server mode
Contains one or more computers configured with server software
Communications
channel
A physical path or a frequency for a signal transmission
Communications
protocol
Set of rules for efficiency transmitting data from one network node to another
Cryptographic
algorithm
A procedure for encrypting or decrypting a message
Cryptographic key
A word, number, or phrase that must be known to encrypt or decrypt a message
CSMA/CD
Carrier sense multiple access with collision detection
Decryption
The process of converting ciphertext into plaintext
DHCP
Dynamic Host Configuration Protocol; a protocol designed to automatically
distribute UP addresses
Drive mapping
Windows terminology for assigning a drive letter to a storage device that’s
located on a different workstation
Encryption
Transforms a message in such a way that its contents are hidden from
unauthorized readers
Ethernet
Most widely implemented network technologies
Ethernet adapter
Installed in a computer if the computer has no Ethernet port
Fast Ethernet
Operates at 100 Mbps
Gateway
A device that joins two dissimilar networks, converting data from one format to
another
Gigabit Ethernet
Operates at 1000 Mbps
Handshaking
Process for Protocols to help two communications devices negotiate and
establish communications
HomePNA
Makes use of a building’s existing telephone cables to connect network nodes
Infrared light
Beams of light to change television channels
IP address
Addresses that identify computers on the Internet
LAN
A data communications network that typically connects personal computers
within a very limited geographical area
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-15
LAN jacking
The interception of signals by cruising through a business district or
neighborhood with a Wi-Fi enabled notebook computer
LAN party
A gathering of people who connect their own computer to a LAN, usually to
play multiplayer computer games
MAC address
A unique number assigned to a network interface card when it is manufactured
MAN
A public high-speed network capable of voice and data transmission within a
range of about 50 miles
Mesh topology
A network topology that connects each network device to many other network
devices, so that data can take any of several possible paths from source to
destination
Microwaves
Electromagnetic signals aimed in a single direction
MIMO
Technology that uses two or more antennae to essentially send multiple sets of
signals between network devices
NAN
A data communications network that provides connectivity within a limited
geographical area, usually spread over several buildings.
Narrowband
Low-bandwidth communications systems
Network attached
storage
A storage device that directly connects to a network
Network device
Any electronic device that broadcasts network data, boosts signals, or routes
data to its destination
Network hub
A device that connects several nodes of a local area network
Network interface
card
Network circuitry required to connect to a LAN
Network router
A network device that can ship data from one network to another
Network switch
Sends data only to the devices specified as the destination
Networked
peripheral
Any device that contains network circuitry to directly connect to a network
Node
Each connection point on a network
Octet
A section of an IP address
Packet
A “parcel” of data that is sent across a computer network
Packet switching
A message is divided several packets that can be routed independently to their
new destination to avoid out-of-service or congested links
PAN
Personal Area Network; a wireless interconnection between devices located not
more than about 30 feet apart
Peer-to-peer mode
Treats every computer as an “equal” so that workstations can run local
applications and also provide network resources
PGP
The public key encryption software used by PC users to encrypt e-mail or other
documents
Physical topology
Layout of devices, wires, and cables on a network
Piconet
Another name for a Bluetooth network
Plaintext
An original message that has not been encrypted
Powerline network
Uses a building’s existing power line cables to connect network nodes
Print server
Handles jobs sent to network printers
Public key encryption
Uses one key to encrypt a message and another key to decrypt the message
New Perspectives on Computer Concepts, Comprehensive, Tenth Edition
Chapter 5-16
RF signals
Radio waves sent and received by transceivers
Ring topology
A network topology that connects all devices in a circle
RJ45 connector
A plastic connector that terminates each end of a network Ethernet cable
Shared resources
Hardware, software, and data that is made available for authorized users via a
network
SSID
The name of a wireless network
Star topology
A network topology that connects all devices arranged around a central
connection point
Strong encryption
Very difficult to break
Symmetric key
encryption
A method in which the key used to encrypt a message is also used to decrypt the
message
Transceiver
Combination of a transmitter and a receiver
Tree topology
A network topology that is a blend of star and bus
WAN
Wide Area Network; covers a large geographical area and may consist of
several smaller networks
War chalking
The placement of specific symbols on walls, sidewalks, or lampposts to signal
other wireless network seekers that they can tap into a wireless network in the
area
Weak encryption
Very easy to decrypt
WEP
Wireless Equivalent Protocol; an encrypting technique used on wireless
networks
Wi Fi
Wireless fidelity operates at 11 Mbps
Wi-Fi card
A network card that contains a transmitter, receiver, and antenna to transmit
wireless signals
Wired network
A network where data travels from one device to another over cables
Wireless access point
Performs same function as a hub or router in a wired Ethernet network;
broadcasts signals to any devices with compatible Wi-Fi cards
Wireless ad-hoc
network
A network in which devices broadcast directly to each other
Wireless encryption
Scrambles the data transmitted between wireless devices and then unscrambles
the data only on devices that have a valid encryption key
Wireless
infrastructure
network
A network that uses a centralized broadcasting device such as a wireless access
point or router
Wireless network
Uses radio frequencies, instead of cables to send data from one network node to
another
Wireless network key
The basis for scrambling and unscrambling the data transmitted between
wireless devices
Wireless router
A wireless access point that also includes routing circuitry that can connect a
Wi-Fi network to the Internet
WPA
Utilizes TKIP to encrypt data based on the user’s password
WPA2
Uses the same kind of strong encryption required by government agencies and
businesses